coord_fixed produces strange error

[drmowinckels]

This is mainly an issue for a better error message when combining plots made with coord_fixed and facets.

The error message is quite cryptic and it tok me a while to figure out that this comes from combinations of coord_fixed and facet_wrap. I'm not sure how feasible it is to catch this and provide a better warning with solution suggestion, but thought it worth making you aware of.

library(ggplot2)
library(patchwork)

# base plots. All below are fine
p1 <- ggplot(mtcars, aes(mpg, disp)) +
  geom_point()

p1 + p1

p2 <- p1 + coord_fixed()

p1 + p2

p3 <- p1 + facet_wrap(~cyl)

p1 + p3

p2 + p3

# These make errors and look weird.

p4 <- p3 + coord_fixed()

p4 + p4
#> Warning in xList[i] <- valueList: number of items to replace is not a multiple
#> of replacement length

#> Warning in xList[i] <- valueList: number of items to replace is not a multiple
#> of replacement length

p1 + p4
#> Warning in xList[i] <- valueList: number of items to replace is not a multiple
#> of replacement length

p2 + p4
#> Warning in xList[i] <- valueList: number of items to replace is not a multiple
#> of replacement length

# fixed with plot_layout(width = 1)
p4 + p4 + plot_layout(width = 1)

^{Created on 2020-03-03 by the reprex package (v0.3.0)}